Atrial fibrillation is a common problem that afflicts millions of patients. Unfortunately, atrial fibrillation often results in the formation of a thrombus, or clot, in the appendage of the left atrium. This presents a problem, inasmuch as the thrombus can dislodge and embolize to distant organs, resulting in adverse events such as a stroke. For this reason, most patients with atrial fibrillation are treated with a blood thinner to help prevent the formation of a thrombus. Blood thinners, however, can present health risks (e.g., bleeding), particularly in the elderly, and often also require that the user make significant lifestyle changes.
Several methods have been developed to address the potential problem of thrombus formation in the left atrial appendage. One such method is suturing along the base, or ostial neck of the appendage, where it joins the atrial chamber. In this way, blood flow into the atrial appendage is cut-off, eliminating the risk of thrombus formation therein. This is typically done through open-heart surgery, making the availability of the procedure available to only those who are otherwise undergoing an open-heart procedure, or who are at particularly high risk. In addition, open-heart surgery requires general anesthesia and has a number of well-known risks, making it less desirable. Furthermore, after the left atrial appendage has been sutured, the tissue may remodel and shrink. Through this process, an area that was tightly closed at the time of suturing may develop leaks over time.
Other methods have also been investigated, including methods of stapling the base of the appendage and methods of filling the appendage with a space occupying or occluding member. However, stapling is not a preferred method given the fragility of the appendage and the likelihood of its rupture. Occlusion devices may not effectively prevent all blood flow into the appendage, leaving areas of potential thrombus formation.
Additional devices and methods for closing the left atrial appendage would therefore be desirable. In particular, devices and methods for closing the left atrial appendage using minimally invasive, intravascular, or a combination of these techniques, would be desirable in order to avoid the need for opening the chest. Of course, additional devices for use in open surgical procedures are desirable as well, especially when those devices offer additional advantages over standard devices.